 They were built and tested for the HARP project but were ultimately not successful due to restrictions in funding and a severe lack of technical information regarding the behavior of large rocket grains  under high acceleration loading.
<clarity>  They were built and tested for the HARP project but were ultimately not successful due to restrictions in funding and a severe lack of technical information regarding the behavior of large rocket grains  under high acceleration loading.
 They were built and tested for the HARP project but were ultimately not successful due to restrictions in funding and a severe lack of technical information regarding large rocket grains under high acceleration loading.