Plus with all the external equipment, ASTOR will be unlikely to fly as high as Global Express. It will not, I understand, be fitted with an AAR probe as the lateral stability is already degraded by the large external fittings and a probe would have pushed it outside the limit (I guess the nose mounted probe shown in the photograph is an instrumentation boom?). Perhaps an AAR slipway so that if could use the boom technique?
8 hours crammed into a bizjet would be bad enough - the prospect of extending beyond that time with AAR would be beyond the endurance of the sensor operators, I would imagine!