site's title and link back to the home page

decorative picture for the mainstream pages Space arrow back A Space Mission From Project to Launch

Whoever or whatever organization may have initiated a mission project, such a project undergoes six phases

->Other Concepts at Nasa!
NASA, generally, since a decade, adopted a cost-reduction approach in term of its space programs, with varied programs focused on that (and the same for the private industries), concept of 'small satellites' -- of which the miniature 'CubeSats,' with 49 launched as of the year 2017 -- which further allows dialog programs with universities. CubeSats were originally created by the California Polytechnic State University in 1999 for educational purposes as such a platform gained popularity among other universities. CubeSats are a class of research spacecraft called nanosatellites as they are built to standard dimensions (Units or “U”) of 10x10x11. They can be 1U, 2U, 3U, or 6U in size, and typically weigh less than 3 lbs (1.33 kg) per U. NASA also, by 2012, is developing its ability to repair and refuel satellites in orbit, especially those not built with servicing in mind and allowing to extend their lifespan. The Space Shuttle was one of the first U.S. program to be used for such repairing in orbit, with the Solar Maximum and Syncom IV successfully repaired in the 1980’s, the Compton Gamma Ray Observatory and Intelsat VI in the 1990’s as it also serviced the Hubble Space Telescope

->How NASA is Managing its New Human Space Programs?
NASA has chosen to part its new crewed programs, after the retirement of the Space Shuttle, into a part -the access to the ISS- left to private companies and a more ambitous part managed by the agency self. In terms of how private companies can participate into crewed launches to the ISS, the NASA released by late 2013 its 'Commercial Crew Program' (CCP), requesting proposals from U.S. companies to complete development of crew transportation systems that meet NASA certification requirements (that phase was called the 'Commercial Crew Transportation Capability' (CCtCap)). A first phase had began in 2012, a certification phase, called 'Certification Products Contracts' (CPC). CPC required companies to deliver a range of products that establish a baseline for their integrated system certification. NASA, generally, intents to leverage the innovative power of industry with the expertise, skill and learned lessons from NASA. As NASA works with U.S. industry partners to develop commercial spaceflight capabilities to low Earth orbit, the agency also is developing by itself the Orion spacecraft and the Space Launch System (SLS), enabling human presence beyond low-Earth orbit across the solar system

Pre-Phase A, Conceptual Study

After that a Science Working Group (SWG) at the NASA headquarters prepared a preliminary concept of the mission, the mission is trusted to one of NASA's centers. Deep space missions, for example, are often trusted to the Jet Propulsion Laboratory, the famed "JPL". An "Announcement of Opportunity" (AO) is sent to scientists, academia, and similar institutions which are able to participate to a space mission. These institutions are making proposals for experiments aboard the mission. Such proposals are reviewed, as a first research about the launch possibilities is performed. Once the project funded, the NASA's center tasks appropriate sections or divisions, and the mission is eventually presented back by the center's personnel to the NASA headquarters. NASA gives or does not give its approval to proceed with the following phase. As far as vehicles to the ISS under the Obama administration are concerned, that phase is called CCDev1 (Initial Concept)

Phase A

That phase involves a mission's concept and requirements definition. It may also be called KDP-A, for Key Decision Point-A as formulation which concerns also the following steps. A preliminary design and a project plan are built. What craft to build, when to launch, cruise, date of arrival at the target, or operations to be carried out, are specified. As are organisations which are to manage the tests and the mission operation, and who the experimenters are. At the end of this phase, the mission has to pass a confirmation review which is addressing significant schedule, technical and cost risks. The mission is or is not confirmed for the development phase. An approval means that NASA has confidence that the spacecraft and the science instruments will be successfully built and launched, and that the science objectives can be successfully achieved. As far as vehicles to the ISS under the Obama administration are concerned, that phase is called CCDev2 (Maturing Design)

Phase B

That phase is about preliminary design and technology development. It phase translates into technical solutions the elements of phase A. Requirements, schedules, and specifications are prepared (SRR, "System Requirements Review"). At this stage new experiments may be devised and added to the mission. Every experiment on the mission is tasked with a team which has to build and operate the related science instruments, and to evaluate the data returned. A member of the team is selected as the Team Leader (TL) and/or the Principal Investigator (PI). The PI may be chosen too as soon as the end of pre-phase A. A PDR ("Preliminary Design Review") is presented at a NASA board of experts who evaluate the mission status and decide whether the mission may continue or not. The design process of the instruments of a mission usually includes a number of different designs, which are all tested to see which would yield the best result for the type of object the instrument would study. For example, various types of infrared cameras may be developed and tested, and the one that gives a scientist the best result, would be chosen to be built as a test unit. Engineering test units, or ETUs are created before an actual instrument is built, so that engineers and scientists can make sure it would work properly. ETUs are also used when engineers are practicing installation of an instrument into a satellite's mainframe or "bus." The outcome of the tests on ETUs may lead to a change in handling procedures of the actual flight instrument, but not a change in its flight construction. Once the ETUs test successful, then the actual instruments that will fly aboard a satellite or space telescope can be manufactured. Those instruments go through their own set of rigorous tests by the manufacturing contractor, NASA and other partners. As far as vehicles to the ISS under the Obama administration are concerned, that phase is called CCiCap (Integrated Design)

Phase C/D

one of both craft of the STEREO mission being assembledone of both craft of the STEREO mission being assembled. picture NASA/Johns Hopkins University Applied Physics Laboratory

Phase C is concerning final design and fabrication as phase D is about system assembly, testing, and launch. Phase C is the phase during which the spacecraft is designed and built. A Critical Design Review (CDR) is taking place. It verifies that the mission design is ready, and is such that one may proceed with the fabrication. Key Decision Point-D (KDP-D) occurs after the project has completed a series of independent reviews that cover the technical health, schedule and cost of the project. The milestone represents the official transition from the mission’s development stage to delivery of systems, testing and integration leading to launch. If such the case, the craft is developped. Subsystems and experiments are built, as they are afterwards integrated into a single spacecraft, in a large "clean room". The complete spacecraft it tested to check whether it's able to endure the harsh space environment. That is performed in the Goddard Space Flight Center, centrifuge, acoustics and thermal vacuum chambers. That last one has been added, for a infrared mission like the next Webb telescope with a helium refrigeration system. Some construction tests may be performed in the constructor's facility. When the satellite is completely assembled, the whole is tested again. If the mission is seemingly large, and not able to be tested in Goddard, it is transported to the Johnson Space Center in Houston, Texas, to be tested in a vacuum chamber that was originally built for testing the Apollo command module. Ground systems which are participating to the mission are developed and tested in parallel with the craft's construction. Last tests are performed between the 7th and the 3rd month before launch, as the science instruments are tested along the last year of preparation. Phase C/D partly overlaps with the next phase, the "Operations phase", as it participates too to launch, deployement, and verification. All along the assembly process instrument or spacecraft components are passed through test chambers to check whether they can endure the harsh conditions of launch and space as the completely assembled craft is eventually tested again

Operations Phase

This is the phase of the operations. The craft is launched and flown, as science missions are performed. Once the tests over, the craft is transported to the launch site by truck or by plane. It's enduring there additional testings and preparations which are focused on operational aspects, like communications, thermal blankets, flight systems, solar arrays, propellant, etc. The spacecraft is then mated to its upper stage as the stack is hoisted atop the launch vehicle. The fairing halves are put into place. The pre-launch and launch sequences are then proceeding. Telecommunications are maintained with the craft to transmit telemetry data to the ground teams. After launch, the appropriate tracking system, like NASA's Deep Space Network (DSN), is acquiring the craft. Such a tracking system is taking the relay from the launch site tracking station. The craft, at last, depending on the mission, is either boosted into orbit, or along an interplanetary trajectory! During a 'commissioning phase,' of varied length, the craft is exposed to the space environment, miscellaneous systems deployed and activated as science data reliability is checked

A Other Example, With The Usages at The European ESA

At the European ESA, the selection process for a mission begins when the agency issues a call to the European science community to suggest scientific themes as proposals are received and assessed by a Senior Survey Committee, and following an extensive interaction with the scientific community a theme is recommended to the Director of Science and Robotic Exploration. The next year, a call for mission concepts is announced to solicit proposals, which can take place as soon as 15 years ahead of the mission

A other example of work schedule at ESA is shown in terms of the steps bringing to a new Ariane launcher. Preparatory activities were approved in November 2012 by the ESA Council at Ministerial level. The concept of the Ariane 6 was selected 7 months after that and on October 1st, the Preliminary Requirements Review of the launch system began as the management plans and the preliminary specifications together with the technical and programmatic files of the concept were submitted for review. That review concluded on November, 6th 2012 as it involved European experts from Arianespace, Italy’s ASI space agency, France’s CNES space agency, the DLR German Aerospace Center and ESA. European customers also participated and contributed to the consolidation of the Mission Requirement Document, which will drive the development. By the end of 2013 further characteristics of the new launcher were set, like the structure in terms of stages and propulsion. By February 2014, a first Design Analysis Cycle will be completed, including trade-offs for several subsystems and a second Design Analysis Cycle will start in March 2013. Results will feed the next System Requirements Review, planned for October–November 2014. ESA meanwhile also consults industry to gather competing ideas on key launcher elements, allowing to the progressive setting up of the industrial organisation, chosing subcontractors for the second Design Analysis Cycle and receiving a industry proposal for the full development of Ariane 6 in preparation for the next ESA Ministerial Council meeting

Website Manager: G. Guichard, site 'Amateur Astronomy,' http://stars5.6te.net. Page Editor: G. Guichard. last edited: 7/18/2016. contact us at ggwebsites@outlook.com
Free Web Hosting