GB2172247A - Launcher for expendable space vehicle - Google Patents

Abstract

A mobile launcher for an expendable space vehicle (ESV) comprises a sea-going vessel [1], for example a modified tanker, having thereon an ESV launch pad [2], means [10] for handling an ESV [11], means [9] for loading a payload package for the ESV [11], means for supporting an ESV [11] for launch, means [14, 15] for transferring fuel to an ESV [11] and a launch operations control centre [4], there being provided also blast protection such as firewalls [3] on the vessel [1] at least in the proximity of the launch pad [2]. A method for launching an ESV into orbit is also disclosed. <IMAGE>

Description

SPECIFICATION Launcher for expendable space vehicle and method of launching same The present invention relates to a launcher for an expendable space vehicle (ESV) and a method of launching an ESV into earth orbit.

ESV's are used to carry payload packages, e.g. satellites, into orbit. A conventional ESV is launched from a land based site. Satellite launches by ESV from such sites are expensive, partly because of the costs of obtaining and maintaining a site suitably remote from inhabitation. Also, the launch azimuth from a land based site is generally restricted by the need to avoid the risk of ESV's overflying populated areas.

The present invention provides a mobile ESV launcher which comprises a sea-going vessel having thereon an ESV launch pad, means for handling an ESV, means for loading a payload package for the ESV, means for supporting an ESV for launch, means for transferring fuel to an ESV and a launch operations control centre, there being provided also blast protection on the vessel at least in the proximity of the launch pad.

The ESV launcher may comprise a modified tanker (e.g. a 'supertanker' or ULCC) having ESV and payload storage facilities provided within the holds. The launch pad may be at or near the bow of the tanker, or on a support structure which may be extended (e.g. cantilevered) from the bow to project in front of the tanker. The launch area is blast protected, e.g. by the use pyrocrete cladding. The deck area around the launch pad may be provided with means adapted to channel and deflect exhaust and flames away from the pad. In the event of a launch failure the ESV can safely fall back into the sea or onto the blast protected deck.Launch is observed and controlled from a launch operations control centre which may be at the stern of the tanker; the control centre may have some blast protection but this may not be necessary where the tanker is sufficiently long as to provide a safe distance between the control centre and the launch pad. Alternatively the launch may be controlled from a remote operations control centre (e.g. from a nearby boat, aeroplane or island).

Much of the equipment and systems for use in handling and supporting an ESV, and launch pad structures, are known in themselves from the field of offshore oil technology and from the aero-space industry.

An advantage of the present invention is that an ESV and its payload (e.g. a satellite) can be loaded onto the vessel at a convenient port in an industrial area and taken to a suitable remote ocean site for launch, thereby removing the need for a costly, permanent, isolated land based site. Furthermore, once at a suitable ocean site, the ESV launcher can conveniently be supplied with additional ESV's, payload packages, fuel etc. by supply vessels.

The invention provides a method of launch ing an ESV into orbit which includes the steps of: i) providing a sea-going vessel having the features described above; ii) loading at least one ESV, at least one payload package and fuel onto the vessel; iii) sailing the vessel to a suitable ocean launch site; and iv) launching a ESV and payload package from the vessel into orbit.

In the case where the vessel is resupplied at sea, the method of the invention includes the steps of: i] providing a sea-going vessel having the features described above; ii] sailing the vessel to a suitable ocean launch site, iii] loading at least one ESV, at least one payload package and fuel onto the vessel, and iv] launching an ESV and payload into orbit from the vessel.

It is a particularly advantageous feature of a method according to the invention that the launch can be made at or near the earth's equator; the angular velocity due to the rotation of the earth is greatest at the equator and thus larger payloads can be carried by an ESV the closer to the equator the launch site is. Thus, according to the invention a cheaper launch with a higher payload can be achieved in comparision to an equivalent conventional launch from a land based non-equatioral site.

It is a further advantageous feature of a method according to the invention that the launch azimuth of an ESV from a mobile launcher at sea is not restricted; this advantage is of particular benefit where satellites are to be launched into specific geo-stationary orbits.

The invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of an ESV launcher according to an embodiment of the invention; and Figure 2 is a side view of the Fig.1 launcher.

As shown in the Figures a mobile ESV launcher comprises a self propelled sea-going vessel 1 having an ESV launch pad 2 mounted on deck. At the stern of the vessel, separated from the launch area by firewalls 3, there are provided a unit 4 housing launch control and accommodation, a unit 5 housing ships facilities and bridge, a heliport 6 and satelite communications dish 7. Payload packages, such as communications and observation satellites for launching into earth orbit, are stored onboard and are readied for use in a preparation bay 8 protected behind the rear firewall 3. A tower crane 9 is provided on deck for loading and offloading of the vessel and for handling the transfer of the payload from the preparation bay 8 to the ESV service tower 10 (shown with doors open).

An ESV 11 is stowed either within a hold on the vessel, or inside the service tower (which is preferably fully enclosed and air conditioned). When the ESV 11 is to be launched, a satellite or other payload package is transferred from the preparation bay 8 to the service tower and loaded into the ESV.

The forward doors of the tower are opened and the ESV is transported on rails 12 across the deck to the launch pad 2 where the ESV is supported by an umbilical tower 13. The ESV 11 illustrated comprises two solid fuel boosters, a liquid fuel sustainer and a load section. At the launch pad, liquid fuel propellant (e.g. hydrazine and liquid 02) is transferred via fuel lines 14 from a cryogenic bay 15 by means of a fault-tolerant automatic propellant handling and loading system.

The deck area around the launch pad has a blast proof protective cladding. Flame buckets 16 and flame exhaust ports 17 are provided to channel and deflect exhaust and flames from the ESV when it is launched. Additionally, high pressure water nozzles 18 are provided on deck to facilitate rapid wash-down of the launch area in the event of any launch failure.

The displacement of the vessel far exceeds the thrust generated by the ESV when it lifts off from the deck, so the effect on the vessels stability is minimal. Generally, the vessel will be maintained in an at least partly ballasted condition so as to maintain a relatively deep draft below mean sea level 19 in order to reduce its motions whilst at sea (i.e. motions due to wind, waves and currents). In the embodiment illustrated, the site chosen for launch is in shallow water and the vessel can be ballasted so that it rests on the seabed 20. This arrangement provides a particularly steady launcher for the launch of the ESV.

Whilst the present invention has been specifically illustrated with reference to the use of an ULCC as the sea-going vessel, it is to be understood that other sea-going vessels could equally well serve the purpose. For example, the invention could be performed using a semisubmersible marine platform, a barge, or a pontoon (e.g. a concrete caisson-type pontoon).

Claims (12)

1. A mobile launcher for an expendable space vehicle (ESV) which comprises a seagoing vessel having thereon a launch pad, means for handling an ESV, means for loading a payload package for an ESV, means for supporting an ESV for launch, means for transferring fuel to an ESV and a launch operations control centre, there being provided also blast protection on the vessel at least in the proximity of the launch pad.

2. A launcher according to claim 1 wherein the vessel is a modified ultra-large crude carrier (ULCC).

3. A launcher according to claim 1 wherein the means for handling an ESV is a deck mounted gantry moveable on rails.

4. A launcher according to claim 1 wherein the means for supporting an ESV for launch and for transmitting fuel to an ESV comprises an umbilical tower supplied with fuel from a fuel store via fuel lines.

5. A launcher according to claim 1 wherein the launch pad is at or near the bow of the vessel and the operations control centre is at or near the stern of the vessel.

6. A launcher according to claim 1 wherein the operations control centre is separated from the launch pad by one or more firewalls.

7. A launcher according to claim 1 wherein the vessel is provided with flame buckets and flame exhaust ports in the deck area around the launch pad.

8. A method of launching an ESV into orbit which includes the steps of: i] providing a sea-going vessel according to any preceding claim, ii] loading at least one ESV, at least one payload package and fuel onto the vessel, iii] sailing the vessel to a suitable ocean launch site and iv] launching an ESV and payload into orbit from the vessel.

9. A method of launching an ESV into orbit which includes the steps of i] providing a sea-going vessel according to any of claims 1 to 7, ii] sailing the vessel to a suitable ocean launch site, iii] loading at least one ESV, at least one payload package and fuel onto the vessel, and iv] launching an ESV and payload into orbit from the vessel.

10. A method according to claim 8 or 9 wherein a satellite is launched into orbit.

11. A launcher, substantially as hereinbefore described with reference to Figs.1 and 2 of the accompanying drawing.

12. A method of launching an ESV into orbit substantially as hereinbefore described with reference to Figs.1 and 2 of the accompanying drawings.