Changes between Version 28 and Version 29 of UserApp/Proba-V

Dec 12, 2011, 1:09:50 PM (8 years ago)


  • UserApp/Proba-V

    v28 v29  
    460460|OIP Space Systems
     462= Proba II =
     464Proba V mission is based on [ Proba II], here you will find a little bit of information about Proba 2
     465== PROBA 2 Mission Summary ==
     467Following on from the success of PROBA-1, which successfully completed its technological goals in its first
     468year of flight and continues to provide valuable scientific data now into its fifth operational year,
     469PROBA-2, now in phase C/D and due for launch in September 2007, will once again fly a suite of new
     470technology demonstrators with an ‘added value’ science package of four experiments. Altogether there are
     471seventeen new developments being flown on Proba-2, divided into two groups: platform technologies which
     472are part of the infrastructure and are mission critical and passenger technologies to gain flight heritage and
     473experience before committing them to the infrastructure of other missions. Of the four Science experiments, two
     474are dedicated to solar physics. The two other will study the space weather (plasma physics)
     475The paper will provide an overview of the PROBA-2 mission and spacecraft along with a description of the
     476scientific payload and technology experiments
     478{| align="center"
     479|[wiki:File:Proba-2-in-orbit-rear-view.jpg 400px]
     481== 1.1. Mission objectives ==
     483The PROBA 2 mission objectives, as deduced from the ESA requirements, can be summarized as follows:
     484 *   PROBA 2 will be a platform to demonstrate and validate new, advanced technologies in order to promote their usage in future missions,
     485 *   As such, PROBA 2 shall accommodate a number of selected technology experiments,
     486 *   PROBA 2 shall furthermore accommodate a series of scientific payloads, in the fields of space environment (plasma) and solar observations;
     487 *   The PROBA 2 system shall be designed to support an in-orbit operational lifetime of 2 years;
     488 *   The PROBA 2 orbit shall be preferably a LEO Sun-synchronous orbit with minimized eclipse time;
     489 *   PROBA 2 shall have a high degree of spacecraft autonomy and ground support automation.
     490== 1.2. Launch and orbit ==
     492PROBA 2 is planned to be launched from Plesetsk, Russia, in September 2007, on a Rockot launcher.
     493PROBA 2 will be a secondary-passenger of the launch of the SMOS (ESA) spacecraft. It will be directly
     494injected in a Sun-synchronous LEO orbit, with an altitude between 700-800 km (baseline 728km) and
     495with the LTAN at 6:00 AM +/- 15 minutes. The orbit injection accuracy provided by the launcher is sufficient
     496to guarantee that the LTAN will remain within 6:00 AM +/- 45 minutes without the use of onboard propulsion.
     497The orbital period is approximately 100 minutes. The targeted orbit is eclipse-free for 9 months per year,
     498thus making the orbit well suited for the solar observing instruments. Maximum eclipse duration during the
     499eclipse season is less than 20 minutes. Since the orbit remains acceptable for the solar
     500observations during the complete mission lifetime, propulsion is not needed to support the mission.
     501However, as is documented below, a propulsion system is accommodated onboard PROBA 2 as a technology
     503== PROBA II Space Segment description ==
     505Like Proba V, PROBA 2 has a weight of less than 130 kg which is 30kg lighter than Proba V and belongs to the class of
     506the mini-satellites . Its structure is built using aluminum and CFRP honeycomb panels. Triple junction Gallium Arsenide solar cells,
     507body mounted on 1 panel and mounted on 2 deployable panels, provide the power to the spacecraft and a Li-Ion
     508battery is used for energy storage. A battery-regulated, centrally switched 28V bus distributes the power to the
     509units and the instruments. A high performance computer, based on the LEON processor provides the
     510computing power to the platform and for instrument data processing. It accommodates the memory for
     511house-keeping data storage as well as a mass memory for the payload image data. The telecommunications
     512subsystem is designed to establish and maintain spaceground communications link with the ground segment
     513while the spacecraft remains sun-pointing. It is CCSDS compatible for up- and downlink in the S-band. The set
     514of ACNS units support Sun-pointing, inertial 3-axis attitude pointing as well as Earth pointing and a series
     515of attitude maneuvers. Furthermore, it performs all required navigation and maneuvering computations
     516onboard. The spacecraft platform provides full redundancy.
     518{| align="center"
     519|+'''PROBA 2 Block Diagram'''
     524== 1.3. Ground segment ==
     526As for PROBA1, the PROBA2 spacecraft will be operated from the Redu Ground station (Belgium).
     527= Proba 3 =
     530Proba-3 is devoted to the demonstration of technologies and techniques for highly-precise formation flying. It consists of two small
     531satellites launched together into a highly elliptical orbit to separate and fly in formation, to prepare for future formation flying
     532missions and characterise sensors and other related technologies.
     534{| align="center"
     535|+'''PROBA 3'''
     540The mission will demonstrate formation flying in the context of a large-scale science experiment, the paired satellites together
     541forming a 150-m distance solar coronagraph with an accuracy down to a few millimetres to study the Sun’s faint corona.
     543The mission is planned to have a lifetime of around two years, following a launch in 2015-2016. The satellites will be launched
     544together in a stack configuration, with the larger ‘coronagraph’ spacecraft on the bottom to provide control and the smaller
     545‘occulter’ spacecraft adopting a more passive role. 
     547Following launcher separation, the stack will perform a series of perigee (or bottom of orbit) burns to raise its apogee (or top of orbit)
     548to 60,524 km. This will be followed by a single apogee burn to raise its perigee to 800 km. After a short preparatory period the
     549two satellites will be separated from each other and injected into a safe tandem orbit with no chance of collision.
     551An approximately three-month commissioning period will follow. One important test will be to demonstrate that the mission’s Collision
     552Avoidance Manoeuvre (CAM) functionality works. The automated CAM is activated in the event that the two satellites grow dangerously
     553close, so they can be left safely in a relative orbit.
     556Nominal operations will include both formation flying manoeuvres and coronagraph observation. The cost in fuel of maintaining formation
     557throughout the orbit would be too great so each orbit will be divided between six hours of formation flying manoeuvres and the two hours
     558closest to Earth in ‘perigee passage’, based on passive drifting with mid-course corrections.
     560Formation flying experiments will routinely take place during the week, with coronagraph experiments being performed during the
     561weekend. The coronagraph experiment will fill the entire 16 gigabit mass memory of its satellite. This data will then be progressively
     562downlinked to the Redu ground station during 20 hours of passes the following week.
     563== Platforms ==
     565Both the larger coronagraph and smaller occulter satellites are derived from the Proba standard platform.
     567The 475 kg coronagraph satellite has a volume of 1010 x 1010 x 1410 mm. It hosts the coronagraph instrument which
     568is pointed directly at the occulter satellite and observes only the corona of the Sun. It has a doubled H-shaped
     569main structure with a set of external panels that make a box for its supporting structure on the port side of the
     570satellite to hold its deployable solar array. There are also further solar cells located on the support structure itself.
     572The satellite’s front panel allows for the opening of the coronagraph instrument, optical metrology sensors and a
     573Sun sensor but no solar cells as this area will be kept in shadow by the occulter satellite during science operations.
     574On the opposite side are another Sun sensor and star trackers. 
     576Its guidance, navigation and control (GNC) system consists of four reaction wheels, six gyroscopes, one star tracker
     577with three heads, six Sun sensors, and two GPS systems and antennas. The majority of the formation flying system is
     578located within the coronagraph satellite as it performs most of the manoeuvres.
     580The 245 kg occulter satellite has a volume of 900 x 1100 x 900 mm. For scientific operations its task is to block
     581the Sun, leaving only the solar corona visible to the coronagraph instrument.
     584It is basically box-shaped, a H-shaped primary structure with all avionics and instrument equipment mounted on the
     585inner panels, with an 1520-mm diameter occulting disk on the face pointing away from the Sun. The opposite side
     586accommodates the satellite’s solar array. Its GNC system consists of four reaction wheels, six gyroscopes, one star
     587tracker with three heads, six Sun sensors and two GPS systems and antennas.
     589The Launch date of Proba 3 is somewhere between 2015-2016 ,expect more info [ here]
    462590= ESA and RTEMS validation and tools =
    469597RTEMS has already been used in several space applications, in particular FedSat (a scientific Research and Development microsatellite), the Surrey's Solid State Data Recorder (a component used in the Disaster Monitoring Constellation), ChipSat (a System-on-Chip architecture), the Electra UHF antenna of the Mars Reconnaissance Orbiter and in the Galileo GIOVE-A and Herschel-Planck satellites.
    470600=  See also =
    473  * [ ESA Proba Missions File:ProbaV Auto6.jpeg]
    474  * [ Aitkenhead File:ProbaV Auto6.jpeg]
    475  * [ PROBA-V File:ProbaV Auto6.jpeg]
    476  * [ Investigation DiBella File:ProbaV Auto6.jpeg]
    477  * [ Official Page File:ProbaV Auto6.jpeg]
    478  * [ ESA Proba1 File:ProbaV Auto6.jpeg]
    480  * [ Autonomous and Precise Navigation of the PROBA-2 Spacecraft File:ProbaV Auto6.jpeg]
    481  * [ Factsheet File:ProbaV Auto6.jpeg]
    482  * [ PROBA-V (Project for On-Board Autonomy - Vegetation) File:ProbaV Auto6.jpeg]
    483  * [ NEWS about Proba2 File:ProbaV Auto6.jpeg]
    484  * [[ ESA]]
    485  * [[ Technical Information for PROBA-2 Laser Tracking Support ]]
     603 * [ ESA Proba Missions 400px]
     604 * [ Aitkenhead 400px]
     605 * [ PROBA-V 400px]
     606 * [ Investigation DiBella 400px]
     607 * [ Official Page 400px]
     608 * [ ESA Proba1 400px]
     610 * [ Autonomous and Precise Navigation of the PROBA-2 Spacecraft 400px]
     611 * [ Factsheet 400px]
     612 * [ PROBA-V (Project for On-Board Autonomy - Vegetation) 400px]
     613 * [ NEWS about Proba2 400px]
     614 * [ ESA 400px]
     615 * [ Technical Information for PROBA-2 Laser Tracking Support  400px]
    486616 * [[ Station Data]]
    487617 * [[ RTEMS Improvement – Space Qualification of RTEMS]]