Mark Adler | |
---|---|
Born | Miami, Florida, U.S. | April 3, 1959
Nationality | American |
Citizenship | American |
Alma mater | University of Florida, California Institute of Technology |
Known for | Adler-32, zlib |
Scientific career | |
Fields | Data compression, Space exploration |
Institutions | Jet Propulsion Laboratory |
Doctoral advisor | Mark Wise |
Website | https://madler.net/madler/ (old website archived at the Wayback Machine and Ghostarchive |
Mark Adler (born 1959) is an American software engineer. He is best known for his work in the field of data compression as the author of the Adler-32 checksum function, and a co-author together with Jean-loup Gailly of the zlib compression library [1] and gzip. [2] He has contributed to Info-ZIP, and has participated in developing the Portable Network Graphics (PNG) image format. [3] [4] Adler was also the Spirit Cruise Mission Manager for the Mars Exploration Rover mission. [5] [6]
Adler was born in Miami, Florida and raised as the only child of David and Bertha Adler. Adler earned his Bachelor of Science in mathematics and Master of Science in electrical engineering degrees from the University of Florida in 1981 and 1985, respectively. In 1990, Adler earned his Ph.D. in physics from the California Institute of Technology. [4]
After his doctorate, Adler worked for Hughes Aircraft in their Space and Communications Group, working on diverse projects including the analysis of the effects of X-ray bursts on satellite cables, development of new error-correcting codes, designing an automobile anti-theft key, and digital image and video compression research (wavelets and MPEG-2). [4]
From 1992 through 1995, Adler was the Lead Mission Engineer on the Cassini–Huygens mission. [4] Afterwards, he became the Mars Exploration Program Architect at the Jet Propulsion Laboratory (JPL) from 1996 through 1998, which meant that Adler was responsible for planning the Mars exploration missions from 2001 on as well as handling inter-project engineering issues for missions in flight and in development during the time. [6] In 1999 and early 2000, Adler was the Mission and Systems Manager and Chief Engineer for the Mars Sample Return project, which was to launch three missions in 2003 and 2005 to bring Martian samples back to Earth in 2008. The project was canceled after the failure of Mars Polar Lander. [6]
Adler initiated and led a three-and-a-half-week study on the concept that was later selected as the Mars Exploration Rover (MER) mission for 2003. He has served as the Deputy Mission System Manager, the Acting Project Engineer, the Deputy Assembly, Test, and Launch Operations Manager, the Landing Site Selection Engineer, and the Spirit Mission Manager. [6]
Adler is currently the project chief of the Low Density Supersonic Decelerator. [7]
Adler is an instrument-rated private pilot, a certified scuba diver, and an amateur theater actor. [8]
He is married to Diana St. James. They live in La Cañada, California. They have two children, Joshua and Zachary. St. James works at the California Institute of Technology and acts in and directs theatrical performances. [4]
Together with co-author Jean-loup Gailly, Adler received the 2009 USENIX Software Tools User Group (STUG) award for their contributions to FLOSS algorithms for data compression. [9]
gzip is a file format and a software application used for file compression and decompression. The program was created by Jean-loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and intended for use by GNU. Version 0.1 was first publicly released on 31 October 1992, and version 1.0 followed in February 1993.
Portable Network Graphics is a raster-graphics file format that supports lossless data compression. PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF)—unofficially, the initials PNG stood for the recursive acronym "PNG's not GIF".
zlib is a software library used for data compression as well as a data format. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. zlib is also a crucial component of many software platforms, including Linux, macOS, and iOS. It has also been used in gaming consoles such as the PlayStation 4, PlayStation 3, Wii U, Wii, Xbox One and Xbox 360.
In computing, Deflate is a lossless data compression file format that uses a combination of LZ77 and Huffman coding. It was designed by Phil Katz, for version 2 of his PKZIP archiving tool. Deflate was later specified in RFC 1951 (1996).
Mars Pathfinder is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight, 10.6 kg (23 lb) wheeled robotic Mars rover named Sojourner, the first rover to operate outside the Earth–Moon system.
Info-ZIP is a set of open-source software to handle ZIP archives. It has been in circulation since 1989. It consists of 4 separately-installable packages: the Zip and UnZip command-line utilities; and WiZ and MacZip, which are graphical user interfaces for archiving programs in Microsoft Windows and classic Mac OS, respectively.
7-Zip is a free and open-source file archiver, a utility used to place groups of files within compressed containers known as "archives". It is developed by Igor Pavlov and was first released in 1999. 7-Zip has its own archive format called 7z, but can read and write several others.
Steven Weldon Squyres is an American geologist and planetary scientist. He was the James A. Weeks Professor of Physical Sciences at Cornell University in Ithaca, New York. His research area is in planetary sciences, with a focus on large solid bodies in the Solar System such as the terrestrial planets and the moons of the Jovian planets. Squyres was the principal investigator of the Mars Exploration Rover Mission (MER).
Lee Daniel Crocker is an American computer programmer. He is best known for rewriting the software upon which Wikipedia runs, to address scalability problems. This software, originally known as "Phase III", went live in July 2002 and became the foundation of what is now called MediaWiki. MediaWiki's code repository was still named "phase3" until the move from Subversion to Git in March 2012.
An aeroshell is a rigid heat-shielded shell that helps decelerate and protects a spacecraft vehicle from pressure, heat, and possible debris created by drag during atmospheric entry. Its main components consist of a heat shield and a back shell. The heat shield absorbs heat caused by air compression in front of the spacecraft during its atmospheric entry. The back shell carries the load being delivered, along with important components such as a parachute, rocket engines, and monitoring electronics like an inertial measurement unit that monitors the orientation of the shell during parachute-slowed descent.
The idea of sending humans to Mars has been the subject of aerospace engineering and scientific studies since the late 1940s as part of the broader exploration of Mars. Long-term proposals have included sending settlers and terraforming the planet. Currently, only robotic landers and rovers have been on Mars. The farthest humans have been beyond Earth is the Moon, under the U.S. National Aeronautics and Space Administration (NASA) Apollo program which ended in 1972.
A Mars landing is a landing of a spacecraft on the surface of Mars. Of multiple attempted Mars landings by robotic, uncrewed spacecraft, ten have had successful soft landings. There have also been studies for a possible human mission to Mars including a landing, but none have been attempted.
Juan R. Cruz is a Puerto Rican aerospace engineer who played an instrumental role in the design and development of the Mars Exploration Rover (MER) and Mars Science Laboratory (MSL) parachute.
Jean-Loup Gailly is a French computer scientist and an author of gzip. He wrote the compression code of the portable archiver of the Info-ZIP and the tools compatible with the PKZIP archiver for MS-DOS. He worked on zlib in collaboration with Mark Adler.
Mars atmospheric entry is the entry into the atmosphere of Mars. High velocity entry into Martian air creates a CO2-N2 plasma, as opposed to O2-N2 for Earth air. Mars entry is affected by the radiative effects of hot CO2 gas and Martian dust suspended in the air. Flight regimes for entry, descent, and landing systems include aerocapture, hypersonic, supersonic, and subsonic.
Curiosity is a car-sized Mars rover exploring Gale crater and Mount Sharp on Mars as part of NASA's Mars Science Laboratory (MSL) mission. Curiosity was launched from Cape Canaveral (CCAFS) on November 26, 2011, at 15:02:00 UTC and landed on Aeolis Palus inside Gale crater on Mars on August 6, 2012, 05:17:57 UTC. The Bradbury Landing site was less than 2.4 km (1.5 mi) from the center of the rover's touchdown target after a 560 million km (350 million mi) journey.
Zopfli is a data compression library that performs Deflate, gzip and zlib data encoding. It achieves higher compression ratios than mainstream Deflate and zlib implementations at the cost of being slower. Google first released Zopfli in February 2013 under the terms of Apache License 2.0.
The Low-Density Supersonic Decelerator or LDSD is a reentry vehicle designed to test techniques for atmospheric entry on Mars. The disc-shaped LDSD uses an inflatable structure called the Supersonic Inflatable Aerodynamic Decelerator (SIAD), which is essentially a donut-shaped balloon, to create atmospheric drag in order to decelerate the vehicle before deploying a large supersonic parachute. The goal of the $230 m project is to develop a reentry system capable of landing 2- to 3-ton payloads on Mars, as opposed to the 1-ton limit of the currently used systems.
Brotli is a lossless data compression algorithm developed by Google. It uses a combination of the general-purpose LZ77 lossless compression algorithm, Huffman coding and 2nd-order context modelling. Brotli is primarily used by web servers and content delivery networks to compress HTTP content, making internet websites load faster. A successor to gzip, it is supported by all major web browsers and has become increasingly popular, as it provides better compression than gzip.
Ashitey Trebi-Ollennu, is a Ghanaian robotics engineer at the National Aeronautics and Space Administration (NASA) and the chief engineer and technical group leader for the mobility and manipulation group at the Jet Propulsion Laboratory He has been associated with various NASA Mars missions, notably the Mars Rover and InSight projects.
gzip was written by Jean-loup Gailly…and Mark Adler for the decompression code.
Within one week, most of the major features of PNG had been proposed, if not yet accepted: delta-filtering for improved compression (Scott Elliott and Mark Adler).…The true glory is really reserved for three people, however: Info-ZIP's Jean-loup Gailly and Mark Adler (both also of gzip fame), who originally wrote Zip's deflate() and UnZip's inflate() routines and then, for PNG, rewrote them as a portable library called zlib; and Guy Eric Schalnat of Group 42, who almost single-handedly wrote the libpng reference implementation (originally pnglib) from scratch.