Hermes (space shuttle)
|Space shuttle Hermes (project discontinued)|
|length||≈ 19 m|
|Takeoff mass (maximum)||21,000 kg|
|Payload in LEO||3,000 kg|
|Bet height||up to 500 km|
Hermes was originally a project of the French Space Agency (CNES) for a manned space shuttle for supply flights in near-earth orbits (LEO). Due to rising development costs, the project was continued in 1987 by the European Space Agency (ESA). The project was discontinued in November 1992 after the financial and political conditions changed.
Hermes was to be launched into space at the tip of an Ariane 5 and consisted of two modules: the resource module, which is disconnected before re-entry into the atmosphere, and the space shuttle itself, which was supposed to land like the space shuttle . In the last version of the planning, before the project was completed, Hermes was supposed to transport three astronauts and three tons of payload. The total mass at launch would have been 21 tons, which was considered the maximum payload of an Ariane 5 Plus.
The development of the space shuttle Hermes can be divided into two phases. The first section contains the development work in the national framework by the French Space Agency (CNES) and the second section takes into account the subsequent European cooperation.
French development work
In 1977, the French Space Agency (CNES) carried out an initial feasibility study for a manned spaceplane called the Hermes. The following years brought considerable success with Ariane 1 (first flight 1979) and NASA's choice to have two Spacelab modules built for the flight with the Space Shuttle , which encouraged the planning accordingly. Instead of a mini space glider on an Ariane 4 (3-man crew with 0.4 t of cargo), in 1978 the company switched to the Ariane 5, which was under development. The conception in 1984 provided for the following parameters:
At the beginning of 1985 the two companies Aérospatiale and Dassault-Breguet began to submit proposals for Hermes to the CNES. The contract was awarded to Aérospatiale at the end of 1985, while Dassault-Breguet was responsible for the aerodynamic design. Due to the estimated total costs of US $ 1.9 billion, including the US $ 1.1 billion for the development and construction of two space gliders, the CNES began promoting the project on a European level.
When ESA started in May 1986, the cost of phase B2 was estimated at US $ 1.5 billion for the development of Hermes. This was viewed as a manned access to the Columbus module. All three projects, Hermes, Columbus and Ariane 5, were approved by ESA in 1987 and were intended to contribute to the expansion of the infrastructure for the International Space Station .
Hermes and Columbus were divided into two phases. Phase 1 includes the conception and the pre-development work and phase 2 includes the completion of the development, the production and the start of operation.
Phase 1 conception and start of development
After the Challenger disaster , it was deemed necessary to incorporate an evacuation capsule to protect the astronauts. Accordingly, the number of seats had to be reduced from six to three. This system was later replaced by ejection seats, with which further weight could be saved. These enable the crew to be evacuated up to a maximum height of 22 to 29 km. Furthermore, the payload was limited to 3 t and the cargo hold was designed as non-opening. The possibility of placing satellites in orbit was thereby dispensed with. The resource module, which was seen as an adapter to the Ariane-5, should also be disconnected before entering the earth's atmosphere, so that a new module has to be attached before each start.
Phase 1 was not yet completed by the end of 1991 when the political framework changed considerably. The Iron Curtain fell and the Cold War ended. In addition, the cost of Hermes and Columbus increased and the weight of Hermes increased to 21 tons. As a consequence, ESA decided to pause for a year to reflect on whether it would still make sense for Europe to build its own space shuttle and space station and whether new partners could be found with whom to share costs and development.
Phase 1 was officially completed at the end of 1992 after a one-year break.
Phase 2 Completion of development, manufacture and start of operation
This phase was never really started because the ESA and the Russian space agency RKA (now Roskosmos) agreed to cooperate on future launches and the exchange of the Mir space station . Economic concerns prevented the RKA from making serious efforts for the space program. At that time, however, ESA had already turned away from the development of a glider system, as required for Hermes, and concentrated on the capsule system, as required by the Russian-European project.
When the RKA, ESA and NASA finally set about building the International Space Station , the need to build a European transport system was eliminated, since both Russia and the USA had sufficient transport capacities. Accordingly, ESA decided to abandon the Hermes project. No part of Hermes has ever been built, but the experience gained was incorporated into other ESA projects, such as the Columbus laboratory module and the "European Retrievable Carrier" EURECA , which remained in space for 318 days. The conception of the Ariane 5 was optimized accordingly for the transport of satellites.
Hermes' budget for 1993–98 was reduced to US $ 405 million and spent on other studies. A total of US $ 2 billion had been invested by the time the project was "completed".
After 1992, developments continued on the following projects:
- the Crew Return Vehicle (CRV) for up to eight astronauts (discontinued);
- two conical or biconical rescue vehicles (Rescue Vehicle RV and Crew Rescue Vehicle CRV) (discontinued)
- the Atmospheric Reentry Demonstrator (ARD), a capsule reminiscent of Apollo with a 2.8 m diameter and 2 m height of 2800 kg to study reentry, flown on Ariane 5 in 1998;
- the Crew Space Transportation System (CSTS), developed in collaboration with Roskosmos and the Japanese Space Agency (discontinued in 2008);
- the Intermediate eXperimental Vehicle IXV (first flight successful on February 11, 2015)
- the DC4EU project (Dream Chaser for European Utilization) is investigating whether and how Europe could use the Dream Chaser technology especially for the start options with the Ariane 5.
- Luc van den Abeelen: Spaceplane HERMES - Europe's Dream of Independent Manned Spaceflight. Springer, Cham 2017, ISBN 978-3-319-44470-3 .
- Hermes in the Encyclopedia Astronautica (English)
- Capcomespace: HERMES, l 'avion spatial inachevé… (French)
- Hermes in the Encyclopedia Astronautica , accessed on May 1, 2011 (English).
- History: Hermes spaceplane, 1987. ESA , accessed on May 1, 2011 (English).
- Corresponding sources are missing. However, description is credible to the other two sources cited.
- Note: There could be differences between the project phase names of that time and the current ones.
- The Manned Space Programs - Program development and achievements to date. ESA , August 1995, accessed May 15, 2011 .
- Big goals: Ariane 5 and Hermes. esa.int, accessed June 11, 2014 .