Changes between Version 6 and Version 7 of TBR/UserApp/Space/Proba_2


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Timestamp:
Nov 29, 2011, 4:58:30 PM (8 years ago)
Author:
Iliyankatsarski
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  • TBR/UserApp/Space/Proba_2

    v6 v7  
    66ever to be flown by ESA, but they are making a big impact in the field of space technology. Proba-2 is the
    77second of the series, building on nearly eight years of successful Proba-1 experience.
     8= ABSTRACT =
    89
     10Following on from the success of PROBA-1, which successfully completed its technological goals in its first
     11year of flight and continues to provide valuable scientific data now into its fifth operational year,
     12PROBA-2, now in phase C/D and due for launch in September 2007, will once again fly a suite of new
     13technology demonstrators with an ‘added value’ science package of four experiments. Altogether there are
     14seventeen new developments being flown on Proba-2, divided into two groups: platform technologies which
     15are part of the infrastructure and are mission critical and passenger technologies to gain flight heritage and
     16experience before committing them to the infrastructure of other missions. Of the four Science experiments, two
     17are dedicated to solar physics. The two other will study the space weather (plasma physics)
     18The paper will provide an overview of the PROBA-2 mission and spacecraft along with a description of the
     19scientific payload and technology experiments
     20= PROBA 2 MISSION SUMMARY =
     21
     22
     23ABSTRACT
     24Following on from the success of PROBA-1, which
     25successfully completed its technological goals in its first
     26year of flight and continues to provide valuable
     27scientific data now into its fifth operational year,
     28PROBA-2, now in phase C/D and due for launch in
     29September 2007, will once again fly a suite of new
     30technology demonstrators with an ‘added value’ science
     31package of four experiments. Altogether there are
     32seventeen new developments being flown on Proba-2,
     33divided into two groups: platform technologies which
     34are part of the infrastructure and are mission critical and
     35passenger technologies to gain flight heritage and
     36experience before committing them to the infrastructure
     37of other missions. Of the four Science experiments, two
     38are dedicated to solar physics. The two other will study
     39the space weather (plasma physics)
     40The paper will provide an overview of the PROBA-2
     41mission and spacecraft along with a description of the
     42scientific payload and technology experiments
     43=  PROBA 2 MISSION SUMMARY =
     44
     45= 1.1. Mission objectives =
     46
     47The PROBA 2 mission objectives, as deduced from the ESA requirements, can be summarized as follows:
     48 *   PROBA 2 will be a platform to demonstrate and validate new, advanced technologies in order to promote their usage in future missions,
     49 *   As such, PROBA 2 shall accommodate a number of selected technology experiments,
     50 *   PROBA 2 shall furthermore accommodate a series of scientific payloads, in the fields of space environment (plasma) and solar observations;
     51 *   The PROBA 2 system shall be designed to support an in-orbit operational lifetime of 2 years;
     52 *   The PROBA 2 orbit shall be preferably a LEO Sun-synchronous orbit with minimized eclipse time;
     53 *   PROBA 2 shall have a high degree of spacecraft autonomy and ground support automation.
     54= 1.2. Launch and orbit =
     55
     56PROBA 2 is planned to be launched from Plesetsk, Russia, in September 2007, on a Rockot launcher.
     57PROBA 2 will be a secondary-passenger of the launch of the SMOS (ESA) spacecraft. It will be directly
     58injected in a Sun-synchronous LEO orbit, with an altitude between 700-800 km (baseline 728km) and
     59with the LTAN at 6:00 AM +/- 15 minutes. The orbit injection accuracy provided by the launcher is sufficient
     60to guarantee that the LTAN will remain within 6:00 AM +/- 45 minutes without the use of onboard propulsion.
     61The orbital period is approximately 100 minutes. The targeted orbit is eclipse-free for 9 months per year,
     62thus making the orbit well suited for the solar observing instruments. Maximum eclipse duration during the
     63eclipse season is less than 20 minutes. Since the orbit remains acceptable for the solar
     64observations during the complete mission lifetime, propulsion is not needed to support the mission.
     65However, as is documented below, a propulsion system is accommodated onboard PROBA 2 as a technology
     66demonstration.
     67= 1.3. Ground segment =
     68
     69As for PROBA1, the PROBA2 spacecraft will be operated from the Redu Ground station (Belgium).
     70= PROBA 2 SPACE SEGMENT DESCRIPTION =
     71
     72PROBA 2 has a weight of less than 130 kg and belongs to the class of the mini-satellites (Figure 1). Its
     73structure is built using aluminum and CFRP honeycomb panels. Triple junction Gallium Arsenide solar cells,
     74body mounted on 1 panel and mounted on 2 deployable panels, provide the power to the spacecraft and a Li-Ion
     75battery is used for energy storage. A battery-regulated, centrally switched 28V bus distributes the power to the
     76units and the instruments. A high performance computer, based on the LEON processor provides the
     77computing power to the platform and for instrument data processing. It accommodates the memory for
     78house-keeping data storage as well as a mass memory for the payload image data. The telecommunications
     79subsystem is designed to establish and maintain spaceground communications link with the ground segment
     80while the spacecraft remains sun-pointing. It is CCSDS compatible for up- and downlink in the S-band. The set
     81of ACNS units support Sun-pointing, inertial 3-axis attitude pointing as well as Earth pointing and a series
     82of attitude maneuvers. Furthermore, it performs all required navigation and maneuvering computations
     83onboard. The spacecraft platform provides full redundancy
     84
     85[http://www.eoportal.org/directory/images/PROBA2_Auto11.jpeg|thumb|none|alt=A |The Wikipede edits ''[wiki:Myriapoda]''. Myriapoda]''.]
     86= 2.1. PROBA 2 platform =
     87= 2.1.1. Mechanical and thermal =
     88
     89The PROBA 2 structure is derived from the PROBA 1 structure and is compatible with launchers such as
     90ROCKOT, PSLV and DNEPR. The carrying part of the structure is composed of 3 aluminum honeycomb panels
     91mounted in an H-structure and a bottom board. Almost all units are mounted on these inner panels. The bottom
     92board acts as the interface with the launcher. All outer panels without solar cells mounted on them consist of
     93aluminum honeycomb panels as well. They are painted black/white according to the needs of the thermal
     94subsystem. The 2 deployable solar panels, as well as one outer panel with solar cells consist of honeycomb
     95panels with aluminum core and CFRP sheets. The sheets supporting the solar cells are covered with kapton
     96for electrical insulation. The deployable panels are permanently connected to the spacecraft body by hinges
     97based on Carpentier joints. The Carpentier joints  provide the opening torque at the moment of panel
     98release as well as the self-locking in the deployed position. During launch, the stowed panels are kept in
     99the stowed condition by the hold-down and release mechanism. This mechanism utilizes thermal knives to
     100release each panel by software command in orbit.
    9101= Providing flight opportunities =
    10102
     
    63155To ensure on board autonomy, mission control system development is an integral part of the overall mission programme, along with the associated operations. Development occurs incrementally, with progressive validation taking place throughout activities ranging from software development, spacecraft integration and system testing to in-orbit operations.
    64156
    65 = External links =
     157=  =External links==
    66158
    67159[http://www.esa.int/esaMI/Proba/SEMJJ5ZVNUF_0.html]