A Mars Spherical Surveyor (MGS) occurs as American spacecraft. Developed by NASA and the Jet Propulsion Laboratory and launched November 1996, it began America's go to to Mars after a Xx-month absence. It completed its primary mission within January 2001, and is at present within a long mission phase.

A Surveyor ballistic capsule, fabricated at a Lockheed Martin Astronautics plant in Denver, is a rectangular-shaped box by using wing-such as projections extending from either paired sides. Once fully loaded by owning propellent at a period of launch, a space vehicle weighed merely 1,060 kg (2,342 pounds). Virtually all of Surveyor's mass lies in a pack-boxlike module occupying the center part of the ballistic capsule. Actually, this center module is mass produced of deuce little rectangular modules built in top of both more. One of them little modules, known as a devices module, holds tons of the ballistic capsule's electronics & science instruments. A more, known as a propulsion module, houses Surveyor's rocket engines and propellant tanks.

Mission chronology

A Surveyor ballistic capsule was launched from either a Cape Canaveral Air Statiin inside Florida on November 7, 1996 aboard a Delta-7925 rocket. the space vehicle traveled about 750 milliin kilometers (466 million miles) all over a course of a 300-day sail to email Mars on September 11 1997.

Upon reaching Mars, Surveyor fired its independent rocket for the Xxii-microscopic Mars orbit insertion (MOI) burn. This maneuver slowed a space vehicle & allowed a planet's gravity to capture it into orbit. At the start, Surveyor entered the extremely elliptical orbit that took 45 hours to complete. the orbit experienced a periapsis of 262 km above a northern hemisphere, & an apoapsis of 54,026 km above a southern hemisphere.

Fallowing orbit insertion, Surveyor performed a series of orbit changes to lower a point of periapsis of its orbit into the upper fringes of the Martian atmosphere at an altitude of astir 110 kilometers (68 miles). When you took each atmospherical pass, the space vehicle slowed down by a cold-shoulder total because of air trend lines. This retardatiin caused the space vehicle to lose altitude on its next pass through the orbit's point of apoapsis. Surveyor utilized this aerobraking technique over a period of little joe months to lower the high point of its orbit from either 54,000 klick to altitudes touching 450 kilometers.

In October 11 a flight team performed a maneuver to raise a point of periapsis away from the atmosphere. This suspension of aerobraking was performed because atmospheric pressure from either a atmosphere stimulated one of Surveyor's ii solar panels to bend backward by the cold-shoulder total. A panel inside wonder was slightly damaged shortly fallowing launch within November 1996. Aerobraking was resumed in November 7 after flight team members concluded that aerobraking was safe, provided that it occurs at a additional gentle pace than projected per original mission project.

Under a recently mission project, aerobraking occurred by owning a moo point of the orbit at an typical altitude of Long hundred kilometre, when opposed to the original altitude of 110 kilometre. This slightly higher altitude resulted inside the decrease of 66% inside terms of air trend lines pressure experient per ballistic capsule. In a time of these vi months, aerobraking decreased the orbit period down to between 12 to 6 hours.

From either Could to November 1998, aerobraking was temporarily suspended to allow a orbit to drift into a proper position using respect to the Sun. Forswearing this hiatus, Surveyor would complete aerobraking by using its orbit in the incorrectly solar orientation. Sequentially to maximize a efficiency of the mission, these captain hicks months were devoted to collecting when much science information as imaginable. Information was become collected between two to 4 days by a day, at the moo point of both orbit.

Eventually, from either November 1998 to March 1999, aerobraking continued & shrank a high point of the orbit down to 450 kilometer. At this altitude, Surveyor circled Mars it used to be that each deuce hours. Aerobraking was scheduled to terminate at a equivalent period a orbit drifted into its proper position using respect to the Sun. In a desired orientation for mapping operations, a ballistic capsule universally crossed the day-side equator at 14:00 (local Mars time) moving from either south to n. This geometry was selected to enhance a sum quality of the science go to.

In a period of mapping operations, the space vehicle circles Mars it used to be that each 117.65 transactions at an typical altitude of 378 kilometers (235 miles). These are inside a polar orbit which is about perfectly round, moving from either existence above a south pole to existence above the northward pole around upright under an hour. A altitude is chosen to produce a orbit sun-synchronous, then that a lot images taken per space vehicle of the equivalent skin-deep features in different dates come taken under monovular lighting conditions.

Fallowing every orbit, a space vehicle has moved Xxviii.62° to the west because Mars has rotated underneath it. Effectively, these are universally 14:00. for Mars Spherical Surveyor when it moves from either once zone to a next exactly when convenient when the Sun.

When 7 sols and 88 orbits, the space vehicle some retraces its former path, however offset by 59 kilometer eastbound. This ensures eventual to the full coverage of the entire surface.

In January 31, 2001, Surveyor completed its primary mission and was approved to enter its extended mission phase.

In March 30, 2004 Surveyor photographed the Mars Exploration Rover Spirit along with its wheel tracks showing its number one 85 sols of travel.

as much as April of 2005, MGS became the number 1 ballistic capsule to photograph a second space vehicle around orbit around a planet otherwise Globe whenever it captured ii images of the Mars Odyssey spacecraft and a single image of the Mars Express spacecraft.

Portions of MGS come scheduled to remain active until at least December 2006 [http://www.msss.com/mars_images/moc/].

MER Communications Subsystem
A ballistic capsule too functions as a communications satellite to relay data back to Globe from either a MER surface landers.