In situ

In situ (/ɪn ˈsɪtjuː, - ˈsaɪtjuː, - ˈsiː-/; often not italicized in English)[1][2][3] is a Latin phrase that translates literally to "on site"[4] or "in position."[5] It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in many different contexts. For example, in fields such as physics, Geology, chemistry, or biology, in situ may describe the way a measurement is taken, that is, in the same place the phenomenon is occurring without isolating it from other systems or altering the original conditions of the test.


In the aerospace industry, equipment on-board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may work but interference from nearby equipment may create unanticipated problems. Special test equipment is available for this in situ testing.


Hohokam Arrowhead Sahuarita Arizona 2014
Ancient Hohokam arrowhead in situ.

In archaeology, in situ refers to an artifact that has not been moved from its original place of deposition. In other words, it is stationary, meaning "still." An artifact being in situ is critical to the interpretation of that artifact and, consequently, of the culture which formed it. Once an artifact's 'find-site' has been recorded, the artifact can then be moved for conservation, further interpretation and display. An artifact that is not discovered in situ is considered out of context and as not providing an accurate picture of the associated culture. However, the out of context artifact can provide scientists with an example of types and locations of in situ artifacts yet to be discovered. When excavating a burial site or surface deposit "in situ" refers to cataloging, recording, mapping, photographing human remains in the position they are discovered.[6]

The label in situ indicates only that the object has not been "newly" moved. Thus, an archaeological in situ find may be an object that was historically looted from another place, an item of "booty" of a past war, a traded item, or otherwise of foreign origin. Consequently, the in situ find site may still not reveal its provenance, but with further detective work may help uncover links that otherwise would remain unknown. It is also possible for archaeological layers to be reworked on purpose or by accident (by humans, natural forces or animals). For example, in a Tell mound, where layers are not typically uniform or horizontal, or in land cleared or tilled for farming.

The term in situ is often used to describe ancient sculpture that was carved in place such as the Sphinx or Petra. This distinguishes it from statues that were carved and moved like the Colossi of Memnon, which was moved in ancient times.


In art, in situ refers to a work of art made specifically for a host site, or that a work of art takes into account the site in which it is installed or exhibited. For a more detailed account see: Site-specific art. The term can also refer to a work of art created at the site where it is to be displayed, rather than one created in the artist's studio and then installed elsewhere (e.g., a sculpture carved in situ). In architectural sculpture the term is frequently employed to describe sculpture that is carved on a building, frequently from scaffolds, after the building has been erected.[7][8] Also commonly used to describe the site specific dance festival “Insitu”. Held in Queens, New York.


A fraction of the globular star clusters in our galaxy, as well as those in other massive galaxies, might have formed in situ. The rest might have been accreted from now defunct dwarf galaxies.

In astronomy, in situ also refers to in situ planet formation, in which planets are hypothesized to have been formed in the orbit that they are currently observed to be in rather than migrating from a different orbit.[9]

Biology and biomedical engineering

Natica hebraea
Live sea snail, species Nataea, photographed in situ

In biology and biomedical engineering, in situ means to examine the phenomenon exactly in place where it occurs (i.e., without moving it to some special medium).

In the case of observations or photographs of living animals, it means that the organism was observed (and photographed) in the wild, exactly as it was found and exactly where it was found. This means it was not taken out of the area. The organism had not been moved to another (perhaps more convenient) location such as an aquarium.

This phrase in situ when used in laboratory science such as cell science can mean something intermediate between in vivo and in vitro. For example, examining a cell within a whole organ intact and under perfusion may be in situ investigation. This would not be in vivo as the donor is sacrificed by experimentation, but it would not be the same as working with the cell alone (a common scenario for in vitro experiments).

In vitro was among the first attempts to qualitatively and quantitatively analyze natural occurrences in the lab. Eventually, the limitation of in vitro experimentation was that they were not conducted in natural environments. To compensate for this problem, in vivo experimentation allowed testing to occur in the original organism or environment. To bridge the dichotomy of benefits associated with both methodologies, in situ experimentation allowed the controlled aspects of in vitro to become coalesced with the natural environmental compositions of in vivo experimentation.

In conservation of genetic resources, "in situ conservation" (also "on-site conservation") is the process of protecting an endangered plant or animal species in its natural habitat, as opposed to ex situ conservation (also "off-site conservation").

Chemistry and chemical engineering

In chemistry, in situ typically means "in the reaction mixture."

There are numerous situations in which chemical intermediates are synthesized in situ in various processes. This may be done because the species is unstable, and cannot be isolated, or simply out of convenience. Examples of the former include the Corey-Chaykovsky reagent and adrenochrome.

In biomedical engineering, protein nanogels made by the in situ polymerization method provide a versatile platform for storage and release of therapeutic proteins. It has tremendous applications for cancer treatment, vaccination, diagnosis, regenerative medicine, and therapies for loss-of-function genetic diseases.[10]

In chemical engineering, in situ often refers to industrial plant "operations or procedures that are performed in place." For example, aged catalysts in industrial reactors may be regenerated in place (in situ) without being removed from the reactors.

Civil engineering

In architecture and building, in situ refers to construction which is carried out at the building site using raw materials. Compare that with prefabricated construction, in which building components are made in a factory and then transported to the building site for assembly. For example, concrete slabs may be in situ (also "cast-in-place") or prefabricated.

In situ techniques are often more labour-intensive, and take longer, but the materials are cheaper, and the work is versatile and adaptable. Prefabricated techniques are usually much quicker, therefore saving money on labour costs, but factory-made parts can be expensive. They are also inflexible, and must often be designed on a grid, with all details fully calculated in advance. Finished units may require special handling due to excessive dimensions.

The phrase may also refer to those assets which are present at or near a project site. In this case, it is used to designate the state of an unmodified sample taken from a given stockpile.

Site construction usually involves grading the existing soil surface so that material is "cut" out of one area and "filled" in another area creating a flat pad on an existing slope. The term "in situ" distinguishes soil still in its existing condition from soil modified (filled) during construction. The differences in the soil properties for supporting building loads, accepting underground utilities, and infiltrating water persist indefinitely.

Computer science

In computer science an in situ operation is one that occurs without interrupting the normal state of a system. For example, a file backup may be restored over a running system, without needing to take the system down to perform the restore. In the context of a database, a restore would allow the database system to continue to be available to users while a restore happened. An in situ upgrade would allow an operating system, firmware or application to be upgraded while the system was still running, perhaps without the need to reboot it, depending on the sophistication of the system.

Another use of the term in-situ that appears in Computer Science focuses primarily on the use of technology and user interfaces to provide continuous access to situationally relevant information in various locations and contexts.[11][12] Examples include athletes viewing biometric data on smartwatches to improve their performance,[13] a presenter looking at tips on a smart glass to reduce their speaking rate during a speech,[14] or technicians receiving online and stepwise instructions for repairing an engine.

An algorithm is said to be an in situ algorithm, or in-place algorithm, if the extra amount of memory required to execute the algorithm is O(1), that is, does not exceed a constant no matter how large the input ---except for space for recursive calls on the "call stack." Typically such an algorithm operates on data objects directly in place rather than making copies of them.

For example, heapsort is an in situ sorting algorithm, which sorts the elements of an array in place. Quicksort is an in situ sorting algorithm, but in the worst case it requires linear space on the call stack (this can be reduced to log space). Merge sort is generally not written as an in situ algorithm.

In designing user interfaces, the term in situ means that a particular user action can be performed without going to another window, for example, if a word processor displays an image and allows the image to be edited without launching a separate image editor, this is called in situ editing.

AJAX partial page data updates is another example of in situ in a Web UI/UX context. Web 2.0 included AJAX and the concept of asynchronous requests to servers to replace a portion of a web page with new data, without reloading the entire page, as the early HTML model dictated. Arguably, all asynchronous data transfers or any background task is in situ as the normal state is normally unaware of background tasks, usually notified on completion by a callback mechanism.

In Big Data space, in situ data would mean bringing the computation to where data is located, rather than the other way[15] like in traditional RDBMS systems where data is moved to computational space.

Design and advertising

In design and advertising the term typically means the superimposing of theoretical design elements onto photographs of real world locations. This is a pre-visualization tool to aid in illustrating a proof of concept.

Earth and atmospheric sciences

In physical geography and the Earth sciences, in situ typically describes natural material or processes prior to transport. For example, in situ is used in relation to the distinction between weathering and erosion, the difference being that erosion requires a transport medium (such as wind, ice, or water), whereas weathering occurs in situ. Geochemical processes are also often described as occurring to material in situ.

In the atmospheric sciences, in situ refers to obtained through direct contact with the respective subject, such as a radiosonde measuring a parcel of air or an anemometer measuring wind, as opposed to remote sensing such as weather radar or satellites.


In economics, in situ is used when referring to the in place storage of a product, usually a natural resource. More generally, it refers to any situation where there is no out-of-pocket cost to store the product so that the only storage cost is the opportunity cost of waiting longer to get your money when the product is eventually sold. Examples of in situ storage would be oil and gas wells, all types of mineral and gem mines, stone quarries, timber that has reached an age where it could be harvested, and agricultural products that do not need a physical storage facility such as hay.


In electrochemistry, the phrase in situ refers to performing electrochemical experiments under operating conditions of the electrochemical cell, i.e., under potential control. This is opposed to doing ex situ experiments that are performed under the absence of potential control. Potential control preserves the electrochemical environment essential to maintain the double layer structure intact and the electron transfer reactions occurring at that particular potential in the electrode/electrolyte interphasial region.

Environmental remediation

In situ can refer to where a clean up or remediation of a polluted site is performed using and simulating the natural processes in the soil, contrary to ex situ where contaminated soil is excavated and cleaned elsewhere, off site.

Experimental physics

In experimental physics in situ typically refers to a method of data collection or manipulation of a sample without exposure to an external environment. For example, the Si(111) 7x7 surface reconstruction is visible using a scanning tunneling microscope when it is prepared and analyzed in situ.

Experimental psychology

In psychology experiments, in situ typically refers to those experiments done in a field setting as opposed to a laboratory setting.


In gastronomy, "in situ" refers to the art of cooking with the different resources that are available at the site of the event. Here a person is not going to the restaurant, but the restaurant comes to the person's home.[16]


In legal contexts, in situ is often used for its literal meaning. For example, in Hong Kong, "in situ land exchange" involves the government exchanging the original or expired lease of a piece of land with a new grant or re-grant with the same piece of land or a portion of that.

In the field of recognition of governments under public international law the term in situ is used to distinguish between an exiled government and a government with effective control over the territory, i.e. the government in situ.


In linguistics, specifically syntax, an element may be said to be in situ if it is pronounced in the position where it is interpreted. For example, questions in languages such as Chinese have in situ wh-elements, with structures comparable to "John bought what?" with what in the same position in the sentence as the grammatical object would be in its affirmative counterpart (for example, "John bought bread"). An example of an English wh-element that is not in situ (see wh-movement): "What did John buy?"


In literature in situ is used to describe a condition. The Rosetta Stone, for example, was originally erected in a courtyard, for public viewing. Most pictures of the famous stone are not in situ pictures of it erected, as it would have been originally. The stone was uncovered as part of building material, within a wall. Its in situ condition today is that it is erected, vertically, on public display at the British Museum in London, England.


In situ carcinoma
In addition to benign tumors, there are in situ tumors and invasive tumors. In situ tumors do not invade the basement membrane, whereas invasive tumors do invade the basement membrane." Diagram of an in situ carcinoma

In oncology: for a carcinoma, in situ means that malignant cells are present as a tumor but have not metastasized, or invaded, beyond the basement membrane of where the tumor was discovered. This can happen anywhere in the body, such as the skin, breast tissue, or lung. This type of tumor can often, depending on where it is located, be removed by surgery.

In anatomy: in situ refers to viewing structures as they appear in normal healthy bodies. For example, one can open up a cadaver's abdominal cavity and view the liver in situ or one can look at an isolated liver that has been removed from the cadaver's body.

In nursing, "in situ" describes any devices or appliances on the patient's body that remain in their desired and optimal position.

In medical simulation, "in situ" refers to the practice of clinical professionals using high fidelity patient simulators to train for clinical practice in patient care environments, such as wards, operating rooms, and other settings, rather than in dedicated simulation training facilities.

In biomedical, protein nanogels made by the in situ polymerization method provide a versatile platform for storage and release of therapeutic proteins. It has tremendous applications for cancer treatment, vaccination, diagnosis, regenerative medicine, and therapies for loss-of-function genetic diseases.[10]


In situ leaching or in situ recovery refers to the mining technique of injecting water underground to dissolve ore and bringing the uranium-impregnated water to the surface for extraction.[17]

Petroleum production

In situ refers to recovery techniques which apply heat or solvents to heavy crude oil or bitumen reservoirs beneath the earth's crust. There are several varieties of in situ techniques, but the ones which work best in the oil sands use heat (steam).

The most common type of in situ petroleum production is referred to as SAGD (steam-assisted gravity drainage) this is becoming very popular in the Alberta Oil Sands.

RF transmission

In radio frequency (RF) transmission systems, in situ is often used to describe the location of various components while the system is in its standard transmission mode, rather than operation in a test mode. For example, if an in situ wattmeter is used in a commercial broadcast transmission system, the wattmeter can accurately measure power while the station is "on air."


Future space exploration or terraforming may rely on obtaining supplies in situ, such as previous plans to power the Orion space vehicle with fuel minable on the moon. The Mars Direct mission concept is based primarily on the in situ fuel production using Sabatier reaction.

In the space sciences, in situ refers to measurements of the particle and field environment that the satellite is embedded in, such as the detection of energetic particles in the solar wind, or magnetic field measurements from a magnetometer.

Urban planning

In urban planning, in-situ upgrading is an approach to and method of upgrading informal settlements.[18]

Vacuum technology

In vacuum technology, in situ baking refers to heating parts of the vacuum system while they are under vacuum in order to drive off volatile substances that may be absorbed or adsorbed on the walls so they cannot cause outgassing.

Road assistance

The term in situ, used as "repair in situ," means to repair a vehicle at the place where it has a breakdown.

See also


  1. ^ Merriam-Webster, Merriam-Webster's Collegiate Dictionary, Merriam-Webster
  2. ^ Iverson, Cheryl, et al. (eds) (2007). "12.1.1 Use of Italics". AMA Manual of Style (10th ed.). Oxford, Oxfordshire: Oxford University Press. ISBN 978-0-19-517633-9.CS1 maint: Extra text: authors list (link)
  3. ^ American Psychological Association (2010), "4.21 Use of Italics", The Publication Manual of the American Psychological Association (6th ed.), Washington, DC, USA: APA, ISBN 978-1-4338-0562-2
  4. ^ Lewis & Short Latin Dictionary
  5. ^ Collins Latin Dictionary & Grammar
  6. ^ Byers, Steven (2011). Introduction to Forensic Anthropology (4th Edition). Upper Saddle Ridge, New Jersey: Pearson Education Inc.
  7. ^ Elise A. Friedland; Melanie Grunow Sobocinski (3 February 2015). The Oxford Handbook of Roman Sculpture. Oxford University Press. pp. 113–. ISBN 978-0-19-026687-5.
  8. ^ Pamela A. Webb (1996). Hellenistic Architectural Sculpture: Figural Motifs in Western Anatolia and the Aegean Islands. Univ of Wisconsin Press. pp. 65–. ISBN 978-0-299-14980-2.
  9. ^ Chiang, E.; Laughlin, G. (1 June 2013). "The Minimum-Mass Extrasolar Nebula: In-Situ Formation of Close-In Super-Earths". Monthly Notices of the Royal Astronomical Society. 431 (4): 3444–3455. arXiv:1211.1673. Bibcode:2013MNRAS.431.3444C. doi:10.1093/mnras/stt424. ISSN 0035-8711.
  10. ^ a b Ye, Yanqi; Yu, Jicheng; Gu, Zhen (2015). "Versatile Protein Nanogels Prepared by In Situ Polymerization". Macromolecular Chemistry and Physics. 217 (3): 333–343. doi:10.1002/macp.201500296.
  11. ^ Ens, Barrett; Irani, Pourang (2017). "Spatial Analytic Interfaces: Spatial User Interfaces for In Situ Visual Analytics". IEEE Computer Graphics and Applications. 37 (2): 66–79. doi:10.1109/MCG.2016.38. PMID 28113834.
  12. ^ Willett, Wesley; Jansen, Yvonne; Dragicevic, Pierre (August 2016). "Embedded Data Representations". IEEE Transactions on Visualization and Computer Graphics. 23 (1): 461–470. doi:10.1109/TVCG.2016.2598608. PMID 27875162. Retrieved 2 October 2018.
  13. ^ Amini, Fereshteh; Hasan, Khalad; Bunt, Andrea; Irani, Pourang (1 October 2018). "Data representations for in-situ exploration of health and fitness data". Proceedings of the 11th EAI International Conference on Pervasive Computing Technologies for Healthcare. PervasiveHealth. BARCELONA, SPAIN: ACM New York. pp. 163–172.
  14. ^ Tanveer, Iftekhar; Lin, Emy; Hoque, Mohammed (2 October 2018). "Rhema: A Real-Time In-Situ Intelligent Interface to Help People with Public Speaking". Proceedings of the 20th International Conference on Intelligent User Interfaces. IGU. ATLANTA, US: ACM New York. pp. 286–295.
  15. ^ Alves, Vladimir (August 2014). "In-Situ Processing Presentation" (PDF).
  16. ^ Gillespie, Cailein; Cousins, John A. (2001). European Gastronomy into the 21st Century. Oxford, UK: Elsevier. p. 72. ISBN 978-0-7506-5267-4. Retrieved 16 June 2014.
  17. ^ In Situ Leach (ISL) Mining of Uranium.
  18. ^ Huchzermeyer, Marie (2009). "The struggle for in situ upgrading of informal settlements: A reflection on cases in Gauteng". Development Southern Africa. 26 (1): 59–74. doi:10.1080/03768350802640099.
Bowen's disease

Bowen's disease, also known as squamous cell carcinoma in situ is a neoplastic skin disease. It can be considered as an early stage or intraepidermal form of squamous cell carcinoma. It was named after John T. Bowen.

Erythroplasia of Queyrat is a particular type of Bowen's disease that can arise on the glans or prepuce in males, and, on the vulva in females, and may be induced by human papilloma virus. It is reported to occur in the corneoscleral limbus.

Carcinoma in situ

Carcinoma in situ (CIS) is a group of abnormal cells. While they are a form of neoplasm, there is disagreement over whether CIS should be classified as cancer. This controversy also depends on the exact CIS in question (i.e. cervical, skin, breast). Some authors do not classify them as cancer, however, recognizing that they can potentially become cancer. Others classify certain types as a non-invasive form of cancer. The term "pre-cancer" has also been used.

These abnormal cells grow in their normal place, thus "in situ" (from Latin for "in its place"). For example, carcinoma in situ of the skin, also called Bowen's disease, is the accumulation of dysplastic epidermal cells within the epidermis only, that has failed to penetrate into the deeper dermis. For this reason, CIS will usually not form a tumor. Rather, the lesion is flat (in the skin, cervix, etc.) or follows the existing architecture of the organ (in the breast, lung, etc.). Exceptions include CIS of the colon (polyps), the bladder (preinvasive papillary cancer), or the breast (ductal carcinoma in situ or lobular carcinoma in situ).

Many forms of CIS have a high probability of progression into cancer, and therefore removal may be recommended; however, progression of CIS is known to be highly variable and not all CIS becomes invasive cancer.

In the TNM classification, carcinoma in situ is reported as TisN0M0 (stage 0).


Cytogenetics is a branch of genetics that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis and meiosis. Techniques used include karyotyping, analysis of G-banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ hybridization (FISH) and comparative genomic hybridization (CGH).

Daniel Buren

Daniel Buren (born 25 March 1938) is a French conceptual artist.


Dysplasia (from Ancient Greek δυσ- dys-, "bad" or "difficult" and πλάσις plasis, "formation") is a term used in pathology to refer to an abnormality of development or an epithelial anomaly of growth and differentiation (epithelial dysplasia).The terms hip dysplasia, fibrous dysplasia, and renal dysplasia refer to an abnormal development, at macroscopic or microscopical level.

Myelodysplastic syndromes, or dysplasia of blood-forming cells, show increased numbers of immature cells in the bone marrow, and a decrease in mature, functional cells in the blood.

Environmental remediation

Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. This would mean that once requested by the government or a land remediation authority, immediate action should be taken as this can impact negatively on human health and the environment.

Remedial action is generally subject to an array of regulatory requirements, and also can be based on assessments of human health and ecological risks where no legislated standards exist or where standards are advisory.

To help with environmental remediation, one can get environmental remediation services. These services help eliminate radiation sources in order to help protect the environment.

Fluorescence in situ hybridization

Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only those parts of a nucleic acid sequence with a high degree of sequence complementarity. It was developed by biomedical researchers in the early 1980s to detect and localize the presence or absence of specific DNA sequences on chromosomes. Fluorescence microscopy can be used to find out where the fluorescent probe is bound to the chromosomes. FISH is often used for finding specific features in DNA for use in genetic counseling, medicine, and species identification. FISH can also be used to detect and localize specific RNA targets (mRNA, lncRNA and miRNA) in cells, circulating tumor cells, and tissue samples. In this context, it can help define the spatial-temporal patterns of gene expression within cells and tissues.

In-situ conservation in India

In-situ conservation is the on-site conservation or the conservation of genetic resources in natural populations of plant or animal species, such as forest genetic resources in natural populations of Teagan species. It is the process of protecting an endangered plant or animal species in its natural habitat, either by protecting or restoring the habitat itself, or by defending the species from predators. It is applied to conservation of agricultural biodiversity in agro ecosystems by farmers, especially those using unconventional farming practices.

In situ hybridization

In situ hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue (in situ) or if the tissue is small enough (e.g., plant seeds, Drosophila embryos), in the entire tissue (whole mount ISH), in cells, and in circulating tumor cells (CTCs). This is distinct from immunohistochemistry, which usually localizes proteins in tissue sections.

In situ hybridization is used to reveal the location of specific nucleic acid sequences on chromosomes or in tissues, a crucial step for understanding the organization, regulation, and function of genes. The key techniques currently in use include in situ hybridization to mRNA with oligonucleotide and RNA probes (both radio-labeled and hapten-labeled), analysis with light and electron microscopes, whole mount in situ hybridization, double detection of RNAs and RNA plus protein, and fluorescent in situ hybridization to detect chromosomal sequences. DNA ISH can be used to determine the structure of chromosomes. Fluorescent DNA ISH (FISH) can, for example, be used in medical diagnostics to assess chromosomal integrity. RNA ISH (RNA in situ hybridization) is used to measure and localize RNAs (mRNAs, lncRNAs, and miRNAs) within tissue sections, cells, whole mounts, and circulating tumor cells (CTCs). In situ hybridization was invented by Mary-Lou Pardue and Joseph G. Gall.

In situ leach

In-situ leaching (ISL), also called in-situ recovery (ISR) or solution mining, is a mining process used to recover minerals such as copper and uranium through boreholes drilled into a deposit, in situ. In situ leach works by artificially dissolving minerals occurring naturally in a solid state. For recovery of material occurring naturally in solution, see: Brine mining.

The process initially involves the drilling of holes into the ore deposit. Explosive or hydraulic fracturing may be used to create open pathways in the deposit for solution to penetrate. Leaching solution is pumped into the deposit where it makes contact with the ore. The solution bearing the dissolved ore content is then pumped to the surface and processed. This process allows the extraction of metals and salts from an ore body without the need for conventional mining involving drill-and-blast, open-cut or underground mining.

In situ resource utilization

In space exploration, in situ resource utilization (ISRU) is the practice of collection, processing, storing and use of materials found or manufactured on other astronomical objects (the Moon, Mars, asteroids, etc.) that replace materials that would otherwise be brought from Earth.ISRU could provide materials for life support, propellants, construction materials, and energy to a spacecraft payloads or space exploration crews. It is now very common for spacecraft and robotic planetary surface mission to harness the solar radiation found in situ in the form of solar panels. The use of ISRU for material production has not yet been implemented in a space mission, though several field tests in the late 2000s demonstrated various lunar ISRU techniques in a relevant environment.ISRU has long been considered as a possible avenue for reducing the mass and cost of space exploration architectures, in that it may be a way to drastically reduce the amount of payload that must be launched from Earth in order to explore a given planetary body. According to NASA, "in-situ resource utilisation will enable the affordable establishment of extraterrestrial exploration and operations by minimizing the materials carried from Earth."


LASIK or Lasik (laser-assisted in situ keratomileusis), commonly referred to as laser eye surgery or laser vision correction, is a type of refractive surgery for the correction of myopia, hyperopia, and astigmatism. The LASIK surgery is performed by an ophthalmologist who uses a laser or microkeratome to reshape the eye's cornea in order to improve visual acuity. For most people, LASIK provides a long-lasting alternative to eyeglasses or contact lenses.

LASIK is most similar to another surgical corrective procedure, photorefractive keratectomy (PRK), and LASEK. All represent advances over radial keratotomy in the surgical treatment of refractive errors of vision. For patients with moderate to high myopia or thin corneas which cannot be treated with LASIK and PRK, the phakic intraocular lens is an alternative. As of 2018, roughly 8 million Americans have had LASIK and, as of 2016, more than 40 million procedures have been performed since 1991.

However, the procedure seems to be a declining option for many in the United States, dropping more than 50 percent, from about 1.5 million surgeries in 2007 to 604,000 in 2015, according to the eye care data source Market Scope.

A study in the journal, Cornea, determined the frequency with which LASIK was searched on Google from 2007 to 2011. Within this time frame, LASIK searches declined by 40% in the United States. Countries such as the U.K. and India also showed a decline, 22% and 24% respectively. Canada, however, showed an increase in LASIK searches by 8%.

By 2015 in the US, LASIK declined by 50%. This decrease in interest can be attributed to a few things: the emergence of refractive cataract surgery, the economic recession in 2008, and unfavorable media coverage from the FDA’s 2008 press release on LASIK.

Lobular carcinoma in situ

Lobular carcinoma in situ (LCIS) is an incidental microscopic finding with characteristic cellular morphology and multifocal tissue patterns. The condition is a laboratory diagnosis and refers to unusual cells in the lobules of the breast. The lobules and acini of the terminal duct-lobular unit (TDLU), the basic functional unit of the breast, may become distorted and undergo expansion due to the abnormal proliferation of cells comprising the structure. These changes represent a spectrum of atypical epithelial lesions that are broadly referred to as lobular neoplasia (LN).

One subset of LN can be defined as LCIS based on specific cellular traits and tissue changes seen histologically. These lesions are preceded by atypical lobular hyperplasia and may follow a linear progression to invasive lobular carcinoma (ILC), with specific genetic aberrations. This process coincides with the progression of ductal neoplasia to ductal carcinoma in situ and invasive carcinoma. Rarely, terminal ducts may be involved in lobular neoplasia, known as pagetoid spread.

Many do not consider LCIS to be a true case of cancer, but it can indicate an increased risk of future cancer. In 2018, the eighth edition of the American Joint Committee on Cancer (AJCC) removed LCIS from tumor staging and considers it a benign entity.


Melanoma, also known as malignant melanoma, is a type of cancer that develops from the pigment-containing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye. In women, they most commonly occur on the legs, while in men they are most common on the back. Sometimes they develop from a mole with changes such as an increase in size, irregular edges, change in color, itchiness, or skin breakdown.The primary cause of melanoma is ultraviolet light (UV) exposure in those with low levels of skin pigment. The UV light may be from either the sun or from other sources, such as tanning devices. About 25% develop from moles. Those with many moles, a history of affected family members, and who have poor immune function are at greater risk. A number of rare genetic defects such as xeroderma pigmentosum also increase risk. Diagnosis is by biopsy and analysis of any skin lesion that has signs of being potentially cancerous.Using sunscreen and avoiding UV light may prevent melanoma. Treatment is typically removal by surgery. In those with slightly larger cancers, nearby lymph nodes may be tested for spread. Most people are cured if spread has not occurred. For those in whom melanoma has spread, immunotherapy, biologic therapy, radiation therapy, or chemotherapy may improve survival. With treatment the five-year survival rates in the United States is 98% among those with localized disease and 17% among those in whom spread has occurred. The likelihood that it will come back or spread depends how thick the melanoma is, how fast the cells are dividing, and whether or not the overlying skin has broken down.Melanoma is the most dangerous type of skin cancer. Globally, in 2012, it newly occurred in 232,000 people. In 2015 there were 3.1 million with active disease which resulted in 59,800 deaths. Australia and New Zealand have the highest rates of melanoma in the world. There are also high rates in Northern Europe and North America, while it is less common in Asia, Africa, and Latin America. Melanoma is more common in men than women. Melanoma has become more common since the 1960s in areas which are mostly populated with white people.

Venus In Situ Atmospheric and Geochemical Explorer

Venus In Situ Atmospheric and Geochemical Explorer (VISAGE) is a proposed Venus lander mission that would perform atmospheric and surface science investigations.

The mission was proposed in 2017 to NASA's New Frontiers program to compete for funding and development, but it was not selected.

Venus In Situ Explorer

The Venus In Situ Explorer (VISE) has been a lander mission concept proposed since 2003 by the Planetary Science Decadal Survey as a space probe designed to answer fundamental scientific questions by landing and performing experiments on Venus.The VISE concept has been identified as a desired theme for mission proposals over several rounds of NASA's competitive mission selections, including those to select the 2nd, 3rd and 4th New Frontiers missions. However, all VISE-themed proposals have thus far been unsuccessful.

Venus In situ Composition Investigations

Venus In situ Composition Investigations (VICI) is a concept lander mission to Venus in order to answer long-standing questions about its origins and evolution, and provide new insights needed to understand terrestrial planet formation, evolution, and habitability.

VICI was one of 12 considerations for New Frontiers 4, but was not one of the two missions selected to be finalists in late 2017.

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