http://www.spacenews.com/launch/110...nch-shavit.html
TEL AVIV, Israel — Faced with a requirement for heavier military spy satellites, Israeli planners have devised an airborne launch concept in which the country’s indigenously built Shavit 2 rocket would be released from a modified Boeing 747 aircraft in international airspace high above the Indian Ocean, sources here said.
Launching far from Israel’s congested airspace and hostile neighbors is emerging as the most likely of several options under review here to preserve Israel’s ability to deploy its most sensitive national security satellites aboard domestically built rockets.
Under the new option gaining traction within some sectors of Israel’s defense and space establishment, the Shavit 2 would be carried under the fuselage of a specially adapted 747 airliner, flown to the Indian Ocean, and launched from altitudes of about 12,000 meters eastward in the direction of Earth’s rotation.
Unlike the U.S. Pegasus rocket, which is dropped bomb-style from an L-1011 carrier aircraft and then maneuvers itself into its launch trajectory, the Israeli concept calls for the Boeing host aircraft to hurl the wingless Shavit 2 into its designated flight path. Sources here say the Israel Air Force aims to do this by pitching the carrier aircraft up to a steep acrobatic performance-style angle to put the space launch vehicle into its required trajectory.
“On a technical level, it’s doable, but it wouldn’t be a comfortable ride in the aircraft at launch,” an Israeli space launch expert here said.
Supporters of the so-called Boeing-boost concept concede myriad technical, operational and potentially diplomatic hurdles ahead, not least of which is how to make an emergency landing with a 31-ton, solid-fueled rocket aboard, assuming Israel could find a nation willing to authorize the landing.
The option also would demand a significant escort package of fighter, refueling and support aircraft to ensure safety and provide tracking and telemetry of the rocket’s flight path. Beyond the budgetary and logistics demands, the escort package risks attracting attention from Africa-based terror groups who might seek to target the aircraft, sources here said.
Nevertheless, they insist that the Boeing-boost option avoids the risk and expense of developing a completely new rocket for launch from Israel’s traditional Palmachim site south of Tel Aviv. Moreover, an Israeli-owned carrier aircraft constitutes sovereign territory, obviating the need for government-to-government agreements or waivers from the Missile Technology Control Regime, which would be required for alternatives such as launching from the territory of another nation.
“Beyond the obvious cost savings involved, it will be a lot easier to explain this [the Boeing-boost concept] compared to a home-based launch of an entirely new ICBM-class [rocket] whose second stage could drop over Tunisia,” another Israeli space expert said.
“It’s not simple, but it may be the best option,” said Tal Inbar, head of Israel’s Fisher Institute Space Research Center. Aside from allowing Israel to preserve its indigenous launching capability, the air-launched option imposes no limits on ultimate inclination of the satellite’s orbit and almost doubles the lifting capacity of the ground-launched Shavit 2, he said.
To avoid launching over enemy countries in the region, Israel launches all of its satellites westward over the Mediterranean, in the opposite direction of Earth’s rotation. Because launches in this direction do not get the added boost provided by Earth’s rotation — some refer to it as a slingshot effect — there is a performance penalty of up to 40 percent, defense and industry sources said.
And given a new Israel Air Force requirement for next-generation spy satellites weighing 700 kilograms — nearly double that of the current Ofeq series of spacecraft — Israel will have to reclaim every bit of lost lift capacity and then some, sources here said.
Maj. Gen. Ido Nehushtan, commander of the Israel Air and Space Force, confirmed the new requirement for significantly larger satellites planned for debut after 2020. He said he was aware of the air-launched option and others under review, but cautioned against overly ambitious undertakings.
“There is a requirement. But I require many things. Will they all become reality? … This whole idea is a little above the pay grade of the [Israel Air Force] alone; this would have to be endorsed as a national-level project,” Nehushtan said.
In a mid-July interview, Nehushtan noted that his service does not own a Boeing 747. “I suppose there’s time to make these decisions. Right now, it seems to me as something out of range, but then again, I don’t want to presume to prejudge it,” he said.
Other sources here say representatives of Israel’s Foreign Ministry, Aviation Authority and legal experts have been informally briefed on the concept. In parallel, the Defense Ministry’s Research and Development Directorate is working on a request for proposals to Israel Aerospace Industries Ltd. and Rafael Ltd. for a feasibility study of the air-launched option.
When asked if Washington or other pro-Western nations might object to Israel’s notional plan to fly a rocket halfway around the world for launching above the Indian Ocean, a senior U.S. State Department official said no, provided that Israel notifies relevant authorities. “As long as the [the rocket] is being launched from an Israeli aircraft; the [rocket] remains in Israeli jurisdiction; and is launched in international airspace following requisite declarations, there should be no grounds for complaints,” the official said.
He noted that Israel would have to specify geographic safety zones and periods of time when the launch would likely take place, as well as places where the first two rocket stages would likely drop off. Such so-called notices to mariners and notices to airmen could be made over a period of days to account for last-minute glitches or bad weather.
IAI, prime contractor for the three-stage Shavit 2 and sole builder of the nation’s military spy satellites, declined comment on the Boeing-boost and other future launch options. As for Rafael, whose Space Propulsion Directorate produces the Shavit’s third stage and has become an industry leader in small hydrazine thrusters, company chairman Ilan Biran said he is waiting to see tangible spending.
“Do we view the space sector as important? Yes. But beyond all the talking, is the Air Force or Ministry of Defense putting any money into such an exotic [research and development] venture?” said Biran, a retired major general and former director-general of the Defense Ministry.
He added, “Real programs like active air and missile defense systems are much more tangible and still in need of funding. Better to focus on the bread before talking about the exotic desert you may never get to eat.”
In addition to the Boeing-boost option, other proposals to preserve Israel’s ability to launch heavier satellites include development of an entirely new rocket much larger than Shavit 2 or adapting the Shavit 2 for sea-based launches in international waters.
Yet another option that has fallen out of favor lately involves launching Shavit 2 from foreign sites such as Brazil’s Alcantara Launch Center, the French-operated Guiana Space Center in Kourou, French Guiana, or even Italy’s dormant San Marco Platform in Kenya.
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07-05-2011, 11:16
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